If ice is warmed and becomes a liquid, the process is endothermic.
The process requires heat in order to proceed. If ice stays in a very cold place, it will not melt unless it's heated. If ice is placed outside where it melts on its own, it gets the heat from the surroundings.
<h2>
<u>A</u><u>n</u><u>s</u><u>w</u><u>e</u><u>r</u><u>:</u><u>-</u></h2>
<em>The female part is the pistil. The pistil usually is located in the center of the flower and is made up of three parts: the stigma, style, and ovary. The stigma is the sticky knob at the top of the pistil. It is attached to the long, tubelike structure called the style.</em>
<h3>
<em><u>H</u></em><em><u>o</u></em><em><u>p</u></em><em><u>e</u></em><em><u> </u></em><em><u>I</u></em><em><u>t</u></em><em><u> </u></em><em><u>W</u></em><em><u>i</u></em><em><u>l</u></em><em><u>l</u></em><em><u> </u></em><em><u>H</u></em><em><u>e</u></em><em><u>l</u></em><em><u>p</u></em><em><u> </u></em><em><u>Y</u></em><em><u>o</u></em><em><u>u</u></em><em><u>!</u></em></h3>
Explanation:
Bond order is inversely proportional to the bond length.
In 
molecule. one nitrogen is double bonded to nitrogen and one oxygen is single bonded to nitrogen and hydrogen bond.
- Bond order between the (N=O) bond is 2 which means that bond length between the (N=O) bond is shorter than that of the N-O bond.
- Bond order between the (N-O) bond is 1 which means that bond length of the N-O bond is longer than that of the bond length of (N=O) bond.
The density of helium is 10 ^-3g.cm^-3
